Let-off mechanism for looms



o.' v PAYNE LET-OFF MECHANISM FOR LOOMS Filed Jan. 5. 1927 2 Sheets-Sheet 1 v Sept. 27,1927. 0 V PAYNE ,643,417

LET-OFF mwmusm FOR LOOMS Filed Jan.5, 1927 2 Sheets-Sheet 2 Patented Sept. 27, 1927.

UNITED STATES PATENT OFFICE.

OSCAR V. PAYNE, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO CROMFTON & KNOWLES LOOM WORKS, OF WORCESTER, IiIASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

LET-OFF MECHANISM FOR LOOMS.

Application filed January 3, 1927. Serial No. 158,534.

This invention relates to a mechanism for controlling the let-off of warp from the warp beam of a loom.

It is the general object of my invention to provide an improved automatic let-off mechanism, by which a very even andvuniform tension will be maintained on the warp during the operation 'of the loom. A further object is to provide means by which the warp may be conveniently adjusted by hand, without changing the tension adjustment of the automatic let-off mechanism.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particu larly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a left hand side elevation of a loom having my improved let-off mechanism applied thereto; 7

Fig. 2 is a view similar to Fig. l, but

showing the parts in a different operative relation;

Fig. 3 is a partial sectional front elevation, taken along the line 3-3 in Fig. 1;

Fig. 4 is a detail sectional rear elevation, taken along the line 44 in Fig. 1;

Fig. 5 is an enlarged bottom view of certain parts of the let-off mechanism, looking in the direction of the arrow 5 in F ig.'1';

Fig. 6 is a similar view but'showing the parts in a different relation and looking in the direction of the arrow 6 in Fig. 2;

Fig. 7 is a detail view of a portion of the warp beam connection, looking in the direction of the arrow 7 in Fig. 3;

Fig. 8 is a detail plan view, looking in the direction of the arrow 8 in Fig. 7;

Fig. 9 is a detail sectional view, taken along the line 9-9 in Fig. 3;

Fig. 10 is a view similar to Fig. 7 but 7 showing a modified driving connection, and

Fig. 11 is a detail. sectional elevation, taken along the line 1111 in Fig. 10.

Referring to the drawings, I have shown a portion of a loom frame 20 supporting a rock shaft 21 for swords 22 which carry the usual lay 23 and reed 24. The warp W is wound on a Warp beam 25 (Fig; 3) commonly having a friction pulley 26 secured thereto, and provided with a gudgeon 27 on which the warp beam is supported, the parts thus far described being of the usual and standard construction.

For the purpose of my invention, I have provided a short shaft or driving member 30 rotatable in a bearing bracket 31 supported by a stand 32 (Fig. 1), such stand being bolt-ed to the loom frame 20. The bracket 31 is vertically adjustable in a guideway on the stand 32, as shown in Fig. 9, and is connected thereto by bolts 33 extending through slots 34 (Fig; 3). By this construction the warp beam may be adjusted vertically as the size of the beam is reduced, thus bringing the delivery point of the warp to the desired elevation, and making it possible to operate the loom without using a separate whip-roll, a construction which is at times extremely desirable.

The shaft or driving member 30 is provided with an arm 35 at one end thereof, having its outer end forked at 36 to receive the end of a lug 37, adapted to be secured by a bolt 38 (Fig. 3) to the inside of the rim of the usual friction pulley26. The shaft or driving member 30 is provided with an axial rgcess 39 to receive and center the gudgeon 2 Y If the pulley 26 is of exceptionally small diameter, it may at times be desirable to re verse the arrangement, securing the lug 37 to'the outer face of the pulley 26, as indicated in Figs. 10 and 11.

A worm wheel 40 is keyed to-the outer end of the shaft 30 and is engaged by a worm 41 (Fig. 2) fixed on a worm shaft 42. The shaft 42 is freely rotatable in bearings 43, 44 and 45 formed on a stand 46. At its upper end, the stand 46 is provided with a slot 47 through which extends a stud 48 mounted on a bracket 49 secured to the frame 20. The lower rear end portion of the stand 46 is loosely pivoted on the shaft 30, as indicated in Fig. 3.

With this construction, the worm 41 maintains a continuous driving engagement with the worm wheel 40 in every vertical position of the warp beam.

The worm shaft 42 has a limited aXial sliding movement in its bearings 43, 44 and 45, and the lower rear end of the shaft 42 is engaged by the short arm of a tension lever 50, pivoted at 51 on the stand 32. Adjustable weights 53 are supported on a hanger 54 which may be positioned in any one of a series of notches 55 on the lever 50.

The weights 53 thus tend to slide the shaft 42 upward and to turn the warp beam rearward or in the direction of the arrow at in Fig. 1, thus tensioning the warp W. At the upper front end of the worm shaft 42 I have provided a hand wheel 57 having a W handle 58, and also having ratchet wheel5,9,

formed on its rearward face.

A feed pawl 60 (Fig. 5) is loosely pivoted on a stud 61 fixed on a supporting member 62 which in turn is pivoted to swing about the axis of the worm shaft .42. The supporting member 62 is provided with spaced bearingportions 63 and 64 which embrace the shaft bearing 45 (Fig. 1) and thus maintain the member 62 in a definite axial p0sition. The member 62 is also provided with a laterall projecting arm 66 (Fig. 4) having a stud 67 to which is pivoted the upper end of a link 68. The lower end of the link is pivoted at69 to an arm 70 fixed to the rock shaft 21 previously described. A light spring "(1 (Fig. 5) is attached at one end to the pawl 60 and at its opposite end to the supporting member 62, and normally maintains the pawl in the inoperative position shown in Fig. 5.

Having described the details of construc tion of my improved let-off mechanism, I will now describe the operation thereof.

In thenormal operation of the loom, the

weights 53, acting through the tension-lever 50, apply pressure to the lower rear end of the worm shaft 42, forcing the shaft upward and forward in itsbearings, and at the same time causing the worm to have a di-' rect action on the worm wheel, like a rack and pinlon, turning the warp beam in the direction of the arrow @111 Fig. 1, and placing the desired tension upon the warp Theparts will remain in this relation asthe warps WV are gradually woven into the cloth and drawn forward by the usual take-up mechanism (not shown). 1

During this forward movement of the warp, the warp beam will be slightly rotated, forcing the worm 41 and worm shaft 42 downward and rearward, and slightly raising the weights 53 but maintaining the warp tension substantially unchanged. During all of this time the feed pawl6O is being regularly oscillated by the link 68 from the rock shaft 21, but the ratchet teeth 59. are displaced forwardly and upwardly so as tobe out of the path of the feed pawl,'a s indicated in Figs. 1 and 5 Gradually, however, the worm 41 :and worm shaft 42 are forced downward and rearward as the warp beam is rotated for: wardly, and after a while the ratchet teeth 5,9.are moved into the path of movement of the ,pawl 60. As soon as the pawl engages one of the ratchet teeth, the pawl will be andturning the worm 411like a screw in the teethof the worm wheel 40. Such movement raises the shaft 42 and lowers the weights '53, whileatthe same time maintaining the uniform tension upon the warp WVhen the worm shaft 42 has been thus'rotated sufliciently to move the ratchet teeth 59. outof thepath. of travel of the pawl 60, the let-oif movement will cease and the parts will thus be restored to the normal running relation shown in Fig. 1.

The let-off mechanism is thus automatic and self-adjusting and continuously restores the tension weights 5 3 to operative relation with the warp beam. The hand wheel 57 and handle .58 areconveniently located so that the weaver may adjust the warp tension or release the same at any time, as required by the conditions of operation, and this may be. done without disturbing the adjustment of the tension lever 50 or. the weights 53 thereon. i 1

During the continued operation of the 100m, the diameter of the warp beam will gradually decrease, and this change maybe taken care of as usual by removal of more or less of the weights 53 or by the adjustment of the hanger 54 to a difierent notch 55 in the tension lever.

Having thus described my invention and the operation thereof, it will be seen that I have provided a very simple and convenient let-ofi mechanism which requires a minimum of attention and which will main tain uniform tension on the warp during the operation of thefloom, while at the same time it maybe very conveniently adjusted by hand for such purposes as may be necessary.

I do not wish to be limited to. the details herein disclosed otherwise than as set forth in the claims, but what I- doclaim is:

1. Inaloom,a warp beamhaving a worm wheel thereon, a worm engaging said wheel, a forwardly extending shaft to which said worm is secured, bearings for said shaft in which said shaftds axially slidable, an automatic feeding device for said shaft, a ten sion leverengaging the rear end of said shaft and effective to move saidshaft axially forward, thereby normally rendering said feedshaft to which said worm is secured, bearings for said shaft in which said shaft is axially slidable, a ratchet on said shaft at its upper front end, a pawlto advance said ratchet, means to regularly move said pawl,

tension means normally effective to hold said ratchet out of the path of said pawl but permitting said pawl to become operative upon continued taking-up of the Warp, and manual means positioned at the upper front end of said shaft and readily accessible for manual adjustment of the warp tension.

3. In a loom, a warp beam having a worm wheel thereon, a vertically adjustable bearing for said warp beam, a worm engaging said worm wheel, a forwardly and upwardly extending shaft to which said worm is secured, bearings for said shaft, a stand for said bearings pivoted on the axis of said worm'wheel and having a pin and slot connection at its front end with the loom frame, and a feeding device for said shaft, operative thereon at the front end thereof, and in every adjusted position of said stand.

4. In a loom let-off mechanism, a ratchet, and a feed pawl mounted for movement about the axis of said ratchet, said ratchet being movable axially into and out of the path of movement of said pawl under the control of the warp tension, and said pawl being yieldingly movable toward said ratchet when engaged thereby.

5. In a loom let-off mechanism, an axially movable ratchet, a supporting member mounted for movement about the axis of said ratchet, a feed pawl pivoted on said member, and yielding means to normally position said feed pawl substantially parallelto the face of said ratchet, said ratchet being movable by war-p tension into the path of said pawl, and said pawl, upon engaging said ratchet, being rocked, on its pivot to cause a full engagement therewith.

In testimony whereof I have hereunto affixed my signature.

OSCAR V. PAYNE. 

